如何使用 Kubernetes go-client 库找到 Pod 的控制器Deployment/DaemonSet？

问题描述

使用以下代码，我可以获取集群中运行的所有 Pod。如何使用 Kubernetes go-client 库找到 Pod 控制器（Deployment/DaemonSet）？

var kubeconfig *string
if home := homedir.HomeDir(); home != "" {
    kubeconfig = flag.String("kubeconfig",filepath.Join(home,".kube","config"),"(optional) absolute path to the kubeconfig file")
} else {
    kubeconfig = flag.String("kubeconfig","","absolute path to the kubeconfig file")
}
flag.Parse()
// use the current context in kubeconfig
config,err := clientcmd.BuildConfigFromFlags("",*kubeconfig)
if err != nil {
    panic(err.Error())
}

// create the kubeClient
kubeClient,err := kubernetes.NewForConfig(config)
metricsClient,err := metricsv.NewForConfig(config)

if err != nil {
    panic(err.Error())
}

pods,err := kubeClient.CoreV1().Pods("").List(context.TODO(),metav1.ListOptions{})

if err != nil {
    panic(err.Error())
}

for _,pod := range pods.Items {
    fmt.Println(pod.Name)
    // how can I get the Pod controller? (Deployment/DaemonSet)
    // e.g. fmt.Println(pod.Controller.Name)
}

解决方法

您通常可以在元数据部分的 ownerReference: 字段中看到管理 Pod 的内容。

示例：

  ownerReferences:
  - apiVersion: apps/v1
    blockOwnerDeletion: true
    controller: true
    kind: ReplicaSet
    name: my-app-6b94f5f96
    uid: 46493c9e-f264-49b8-9f52-d1d919aedbf2

,

按照@Jonas 的建议，我找到了 Pod 的经理。这是一个完整的示例：

package main

import (
    "context"
    "flag"
    "fmt"
    metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    "k8s.io/client-go/kubernetes"
    "k8s.io/client-go/tools/clientcmd"
    "k8s.io/client-go/util/homedir"
    "path/filepath"
)

func main() {
    var kubeconfig *string
    if home := homedir.HomeDir(); home != "" {
        kubeconfig = flag.String("kubeconfig",filepath.Join(home,".kube","config"),"(optional) absolute path to the kubeconfig file")
    } else {
        kubeconfig = flag.String("kubeconfig","","absolute path to the kubeconfig file")
    }
    flag.Parse()
    // use the current context in kubeconfig
    config,err := clientcmd.BuildConfigFromFlags("",*kubeconfig)
    if err != nil {
        panic(err.Error())
    }

    // create the kubeClient
    kubeClient,err := kubernetes.NewForConfig(config)

    if err != nil {
        panic(err.Error())
    }

    pods,err := kubeClient.CoreV1().Pods("").List(context.TODO(),metav1.ListOptions{})

    if err != nil {
        panic(err.Error())
    }

    for _,pod := range pods.Items {
        if len(pod.OwnerReferences) == 0 {
            fmt.Printf("Pod %s has no owner",pod.Name)
            continue
        }

        var ownerName,ownerKind string

        switch pod.OwnerReferences[0].Kind {
        case "ReplicaSet":
            replica,repErr := kubeClient.AppsV1().ReplicaSets(pod.Namespace).Get(context.TODO(),pod.OwnerReferences[0].Name,metav1.GetOptions{})
            if repErr != nil {
                panic(repErr.Error())
            }

            ownerName = replica.OwnerReferences[0].Name
            ownerKind = "Deployment"
        case "DaemonSet","StatefulSet":
            ownerName = pod.OwnerReferences[0].Name
            ownerKind = pod.OwnerReferences[0].Kind
        default:
            fmt.Printf("Could not find resource manager for type %s\n",pod.OwnerReferences[0].Kind)
            continue
        }

        fmt.Printf("POD %s is managed by %s %s\n",pod.Name,ownerName,ownerKind)
    }
}